What is Encrusting?

'Encrusting' is a term coined by Rheon perfectly explaining how its co-extrusion equipment can have a filling that is 'encrusted' with an outer material, for example in a Scotch egg; the egg is encrusted with pork meat. However the encrusting equipment Rheon makes is so much more flexible than just co-extrusion and they use the laws of Rheology to create high quality foods. 

The basics of an encrusting machine

Nearly all encrusting machines from Rheon have six standard types of product you can make from the one machine without requiring further options. They come as standard.


One material can be divided in a round shape, some examples are doughballs, falafel or meatballs.

Bar Shaped

One material can be divided into an elongated bar shape, an example is a kofte kebab.

Continuous Extrusion

One material can be continuously extruded and cut with a guillotine, an example would be cheesecake or cheese strips.

Sherical Encrusting

Two materials can be encrusted into a round shape, examples are picnic eggs, mini falafel, fishcakes.

Bar Shaped Encrusting

Two materials can be encrusted in a bar shape, an example is the popular pork and chopped egg bar covered in breadcrumbs.

Continuous Co-extrusion

Two materials can be continuously co-extruded and cut with a guillotine an example would be sausage rolls or fig rolls.

and then some......

Three Fillings

There are many options from Rheon for further shaping or filling of products which can be explored in the equipment section but by simpling adding a double filling feeder pump or a solid feeder, three materials can be used, for instance minced beef on the outside with a filling of mozarella and a filling of pesto in the middle of the cheese to make a delicious type of meatball

Key to Rheon Encrusting

Retention Time

The encruster come with two hoppers for extruding one or two materials together, the time from the product entering the system in the hopper to exiting the system at the nozzle as a formed product is kept to a minimum to reduce the pressure.

Material Flow

The Rheological flow of the materials have been considered and evolved through the 60 years worth of evolution of the encruster. The materials take a smooth, constantly moving route around the system for least pressure.

Open Ended

The encruster system is open ended on exiting the machine so there is less pressure build up on the materials. The materials are assisted mechanically for reducing the friction and pressure. 

Material Movement

The flow controllers move the materials through the sytem, they move in the natural Rheological direction of flow for easing pressure and they release air from the system to ensure accurate final product weight control. No vacuum is used.


The encruster has evolved though constant development and customer insight, it is now more compact, simplified for use, simplified for maintenance and hygiene but still retains its flexibility and versatility.

The Most Important Part

The encruster is a powerful machine but gentle to the materials and can retain good eating qualities in the final product. Fish is still flaky, course meat grind is still course, particulates are still whole and the gluten structure in dough is retained.

See the benefits of the Encrusters in action

There are so many benefits to a Rheon encrusting system, the shaping of the final product, the accurate centralisation of the filling in the outer material, the range of options that can make other types of products. The link below takes you to the equipment page to find out more about encrusting and see the latest devlopment of the KN551 Encruster, Rheon's most versatile machine.